Circuit breaker

ABSTRACT

A &#39;&#39;&#39;&#39;trip&#39;&#39;&#39;&#39; indicative circuit breaker having an improved operating mechanism for switching contacts is provided. Respective components of the operating mechanism are all pivoted compactly between two parallel plates, forming a linkage from detected excess-current responsive piece, through engagingdisengaging frame and turning arm engageable at a slidable-pivot end with the frame, to operating plate coupled at rotatable side to intermediate portion of the arm and an external manual handle. The arm is coupled at the other end to carrier member for opening and closing breaker contacts. When the responsive piece is actuated by detected excess-current, the linkage is broken between the frame and the arm to free the carrier member causing the contacts opened and the handle positioned to &#39;&#39;&#39;&#39;trip&#39;&#39;&#39;&#39; indicative position. The linkage is restored by handle rotation toward OFF position.

United States Patent 1191 Yoshino et a1.

[ CIRCUIT BREAKER [7 5] Inventors: Akira Yoshino; Hitoshi lmanishi,

both of Seto, Japan [73] Assignee: Matsushita Electric Works, Ltd.,

Osaka, Japan [22] Filed: Apr. 3, 1974 [2]] App]. No.: 457,418

[30] Foreign Application Priority Data Apr. 6, I973 Japan 48/39934 Apr.6, 1973 Japan 48/39935 Apr. 6, 1973 Japan 48/39938 52 US. (:1 335/6,335/21, 335/190 [51] Int. Cl. H0lh 77/06 [58] Field of Search 335/6,202, 201, 190,21,

[56] References Cited UNITED STATES PATENTS 3,204,063 8/1965 Nash et al337/46 3,742.401 6/1973 Strobel 335/21 Primary Examiner-Harold BroomeAttorney, Agent, or Firm-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd;

- ABSTRACT A trip indicative circuit breaker having an improvedoperating mechanism for switching contacts is provided. Respectivecomponents of the operating mechanism are all pivoted compactly betweentwo parallel plates, forming a linkage from detected excess-currentresponsive piece, through engaging-disengaging frame and turning armengageable at a slidable-pivot end with the frame, to operating platecoupled at rotatable side to intermediate portion of the arm and anexternal manual handle. The arm is coupled at the other end to carriermember for opening and closing breaker contacts. When the responsivepiece is actuated by detected excess-current, the linkage is brokenbetween the frame and the arm to free the carrier member causing thecontacts opened and the handle positioned to trip indicative position.The linkage is restored by handle rotation toward OFF position.

5 Claims, 37 Drawing Figures PATENIEL v 3,851,284

' Sam on N15 PATENTEL MWZ 3 851 .2834

saw 01 or 16 PATENTEL NOV 2 6 I974 sum 09 HF 16 Fig.

cmcurr BREAKER This invention relates to circuit breakers and, moreparticularly, to an operating mechanism for driving a switching contactpart in a circuit breaker having a trip indicating function.

In the circuit breaker in which such component part arrangement as, forexample, in the embodiment ofthepresent invention is made, in order toeffectively use the space within the apparatus or to obtain many meritsin the assembling step, an operating mechanism of a thin type havingoperating mechanism parts incorporated between two plate memberscombined with each other at a spacing of about 1 cm and arranged inparallel with each other in front of the apparatus and provided with anoperating handle operated in the direc- 7 tion parallel with said platemembers in front of the plates will be very useful in some case.

However, in the general conventional apparatus of this kind, as theoperating handle is pivoted over bearing plates as fitted upright infront of the apparatus and the operating mechanism is assembled ascorrelated with another operating mechanism not arranged between thebearing plates with saidv operating handle as a center, suchrequirements as are described above have not been met. The presentinvention is suggested to improve the above mentioned defects.

A main object of the present invention is to provide a simple operatingmechanism which is so thin as to be housed in a chassis.

Another object of the present invention is to provide an operatingmechanism unit which can be assembled by only putting in the respectivecomponent parts and combining two plate members by calking. I

A further object of the present invention is to provide an operatingmechanism wherein a turning arm can be moved by enlarging an operatingforce for an excess current detecting element.

Other objects and advantages of the present invention will be made clearby the following description of the invention detailed with reference toa preferred embodiment in conjunction with accompanying drawings, inwhich:

FIG. 1 is an explanatory view showing schematically the arrangement of acircuit breaker of the present invention;

FIG. 2 is an upper surface view of the apparatus of the presentinvention;

FIG. 3 is a lower surface view ofthe same with a back lid removed;

FIG. 4 is a side view of the same;

FIG. 5 is a view showing the interior with a part of a cover cut off;

FIG. 6 is an upper surface view shown with the cover removed;

FIG. 7 is an upper surface view in FIG. 6 shown with an upper lidremoved;

FIG. 8 is a lower surface view in FIG. 3 with a lower lid removed;

FIG. 9 IS a sectioned view shown along an input terminal and outputterminal in FIG. 6;

FIGS. 10A through 10C are upper surface view, lower surface view andvertical sectioned view substantially at the centre of a chassis;

FIG. 11 IS a cross sectional view along a carrier of the chassis;

FIG. 12 is a perspective view of an operating part;

FIG. 13A is a perspective view of the operating part as disassembled,and FIG. [33 shows main elements in the operating part;

FIG. 14A is a front view of the operating part as assembled;

FIG. 14B is a rear view of the same;

FIG. 14C is a side view of the same;

FIG. 15 is a perspective view of an electromagnet employed in thedevice;

FIGS. 16A through 16C show a coil in the above; FIG. 17 is a perspectiveview of a switching contact unit;

FIG. 18 is a perspective view of a carrier;

FIG. 19 is a perspective view of an armature;

FIG. 20 is an elevation of a handle;

FIGS. 21 and 22 are fragmentary sectioned views for explaining theoperating part as fitted;

FIGS. 23A, B and C are views for explaining the operation of theoperating part;

FIGS. 24A through 24C are views for explaining the operation of thecontact plate;

FIGS. 24A through 24C are fragmentary sectioned views showing operationsof contacting plate; and

FIGS. 25A and 25B are explanatory views showing operative relationbetween certain main elements in the operating part.

FIG. 1 shall be explained in the following.

FIG. 1 shows a unit arrangement ofa circuit breaker of the presentinvention. In the drawing, INPUT is an input terminal, OUTPUT is anoutput terminal and these terminals are arranged on both sides of a caseA. B is a switching terminal. C is an excess current detecting part. Dis an operating part. An upper space and lower space are formed by apartition wall E in the case A. The operating part D is arranged in theupper space. The switching contact part B and excess current detectingpart C are arranged in the lower space. F is an operatively connectingplate integrally having an armature for transmitting the operation ofthe excess current detecting part C to the operating part D. F is acarrier for transmitting the operation of the operating part to theswitching contact part. The electric current path is from the inputterminal through the switching contact part B and excess currentdetecting part C to the output terminal OUTPUT. The operation sequenceis from the excess current detecting part C through the operativelyconnecting plate F, operating part D and carrier F' to the switchingcontact part B. G is a handle. The operating part D is manually operatedby the handle G so as to make ON and OFF.

FIG. 2 shows an upper surface view, in which 57 is a handle to berotated so as to have three positions of U, V, and W within a fan-shapedconcave part 68 pro.- vided on a cover 65. The trip is indicated by ared mark appearing in an indicating window hole 62 made on the uppersurface of the case. is a set screw used to fit the cover 65 to thechassis.

FIG. 3 is a lower surface view showing the circuit breaker of thepresent invention with the bottom plate removed. Thin parts 69 areprovided on the side wall 65a of the cover 65 so that electric wires 66may be inserted and fitted within the unit by removing said parts. I isa chassis, and 64 is its lower lid.

FIG. 4 shows a side view of the circuit breaker. A handle 57 isrotatably provided on the cover 65. 69 is a thin part.

FIG. 5 shows a vertically sectioned view of the above. The electricwires 66 are fitted to the chassis 1.

FIG. 6 is an upper surface view of the device in FIG. 1 shown with thecover 65 removed. 5 and 6 are respectively an input terminal and outputterminal. A fanshaped indicating plate 63 is fixed integrally with thehandle 57 to the lower part of the handle 57. A trip indicating part 630is provided on this indicating plate so that, with the rotation of thehandle 57, the trip indicat- .ing part 63a will move and that, when theindicating part 63a is positioned below the indicating window hole 62 ofthe lid 59, the trip state will be indicated. 59b is a concave part madeon the upper lid 59. 59C. is an edge of the lid.

FIG. 7 is a view showing the interior of the device shown in FIG. 6 withthe upper lid 59 removed.

In the drawing, the operating part D is secured between both side walls2 of the chassis 1. There are shown a carrier F (indicated by 22 in thedrawing) operated by said operating part D and an operatively connectingplate F (indicated by 25 in the drawing) operated by the excess currentdetecting part C.

FIG. 8 is a view shown in FIG. 3 with the lower lid 64 removed. Thereare shown the excess current detecting part C, switching contact part Band operatively connecting plate F (25) operated by the excess currentdetecting part C. 1

FIG. 9 is a vertically sectioned view of the device of the presentinvention and is a detailed view corresponding to FIG. 1. There areshown the input terminal a(5 switching contact part B, excess currentdetecting part C, operatively connecting plate F, operating, part D,carrier F and output terminal b(6). The excess current detecting part Cand operating part D are arranged as separated above and below thepartition wall E(3) of the case. j

FIGS. 10A through 10C show a chassis A(I), wherein FIG. 10A is an uppersurface view thereof. The operating part D (not illustrated here) isfitted in the space between the side walls 2. 71 is a hole for fittingthe operating part D. The space is sectioned into an upper space andlower space by a partition wall 3. 72 and 73 are communicating windowsmade in the partition wall 3.. The carrier F (not illustrated here) isinserted into theicommunicating window 72 and the operatively connectingplate F (not illustrated here) is inserted into the communicating window73. FIG. 10B is a lower surface view. The communicating windows 72 and73 are seen between the side walls 2. 74 is a partition wall for housingthe elements forming the excess current detecting part C as describedlater. FIG. 10C shows a vertically sectioned view of the chassis. Thereare shown the partition wall 3 and communicating windows 72 and 73.

FIG. 11 is a sectioned view of the device along the communicating window72, wherein the carrier 22 (or F) is shown here.

Now the formation of each part shall be detailed.

FIG. 12 shows an operating part unit. FIG. 13A

shows the respective elements thereof as disassembled in a perspectiveview. The above described operating part D is held between two groundplates 33 and 33'. 39 is an arcuate groove made in the ground plates. 75is a hole made in each ground plate, in which the long leg 37a of alater described U-shaped shaft 37 is pivoted. Said U-shaped shaft 37 hasa long leg 37a and short leg 37b. In an operating plate 38 formed to beU- shaped by bending two plates, there are formed two holes 38a and 38band a calked pin 38c inside. The long leg 37a of the shaft 37 isinserted through the hole 38a of the operating piece 38 and is insertedinto the hole of the ground plate 33. The short leg 37b is inserted intothe hole 38b of the operating piece through a roller 76 contained insidethe operating piece 38 (see FIG. 12). That is, the operating piece 38 isfitted to the ground plates 33 and 33' so as to be rotatable with theshaft 37a as a center. 40 is a turning arm provided with a tip part 40aas somewhat inclined at one end, with a hole 40c at the other end andwith a projection 40b in the substantially intermediate part. A shaft 41is inserted in the hole 40c of the turning arm 40. Further, the turningarm 40 is inserted in the intermediate part (between the hole 400 andprojection 40b) into the intermediate part (between the hole 38b and pin38c) of the operating plate 38 (see FIG. 12B). 42 is a hanging framebent to be a U-shaped. 42a is its connecting part. 42b is a pivotinghole. The hanging frame 42 has at its tip engaging parts 44 with whichthe shaft4l of the turning arm 40 is to be engaged and inclined parts45. The ground plates 33 and 33' are combined with each other with afixed space between them by inserting the projections at both ends ofcalked rivets 34 into the holes 330 and 33'a. The operating plate 38 isrotatably supported between both ground plates with the long leg 37a ofthe U-shaped shaft 37 inserted in the holes 75 of the ground plates 33and 33'. The hanging frame 42 is rotatably supported by the groundplates with a shaft 43 inserted in the hole 42b of the hanging frame andthe holes 33b and 33'b of the ground plates. 49 is a re- 1 spondingpiece formed to be substantially L-shaped and having a bent part 49bformed at one end, a pivoting hole 49c formed at the other end aprojection 52 formed on the side opposite the bent part 49b. Theresponding piece 49 is rotatably supported between the ground plates 33and 33 by inserting a shaft 50 in the hole 490 of the responding piece49 and the respective holes 330 and 33'c of the ground plates 33 and33'.

The above mentioned responding piece, hanging frame and turning armareso arranged that, as shown in FIG. 13B, the tip parts 49a and 52 ofthe responding piece 49 will-be engageable with the bent part 42a of thehanging frame 42 and the shaft 41 inserted in the hole 400 of theturning arm 40 will be contactable with the engaging part 44 andinclined part 45 of the hanging frame 42. A spring 51 is insertedbetween the projection 54 of the responding piece 49 and the bentprojection 53 of the ground plate 33 so as to give a counter-clockwisepressing force to the responding piece 49. A spring 56 is engaged at oneend with the short leg 37b of the U-shaped shaft 37 and at the other endwith the hole 33d of the ground plate 33 so as to give "a clockwisetorque to the operating plate 38. 46 is all shaped spring inserted atthe open end 46b in the holes 48 of the ground plates 33 and 33,-engagedin the intermediate part 46a with the cut and raised parts 47 of theground plates 33 and 33' and contacted at the other end 46c with thesides 44d of the engaging parts 44 so as to give a clockwise torque tothe engaging parts 44. The thus formed state is shown in FIGS. 14Athrough 14C, in which FIG. 14A shows a front view of the operating part.FIG. 14B shows its rear view and FIG. 14C shows its side view.

FIGS. 15 and 16A through 16C show an oil dash pot type electromagneticdevice employed as an excess current detecting part. It is formed of acoil 17, coil frame 18, L-shaped yoke 20 and oil dash pot 20'.

FIG. 17 shows a switching contact unit, in which a movable contact 13 isprovided at the tip of a contact plate 12, a hole 12a is provided in theintermediate part, a middle leg a of an E-shaped supporting metal piece10 is inserted in the hole 12a, the contact plate 12 is embraced on thesides by hooked parts provided at the tips of both legs 10b and 100 andthe contact plate 12 is supported rotatably on the supporting metalpiece 10 by a coil spring 77 fitted on the middle leg 10a. 78 is aterminal metal piece connected with the contact plate 12 through a leadwire 15.

FIG. 18 shows the carrier 22 (or F) in which grooves 22a for insertingthe contact plate 12 are made on the lower side and a stepped part 24 tocontact the turning arm 40 is made on the upper side as described later.

FIG. 19 is of an operatively connecting plate to which is fixed anarmature 25 formed of a turning plate 27, to the lower side of which isfixed an iron piece 26 with a pin 29 and in a part of which is provideda projection 25' to push the bent part 4% of the responding piece 49. 30is a supporting shaft provided to project at each end of the operativelyconnecting plate so as to rotat ably fit the plate to the chassis 1 asdescribed later.

FIGS. 20 and 22 show the handle 57 made of a synthetic resin. 57a is ahole in which the long leg 37a of the U-shaped shaft 37 is to beinserted and which is made through the handle 57. 57b is a hole in whichthe short leg 37b is to be inserted and which does not pass through thesurface.

Now the assembly of the device of the present invention shall beexplained.

The respective leg parts 5b and 6b of the L-shaped input terminal metalpiece 5 and output terminal metal piece6 are inserted respectively inthe concave parts In and lb of the chassis I (see FIGS. 7, 8, 9 and 10)made of an insulator. Wire fastening screws 7 are fitted to therespective upper pieces 5a and 6a of the terminal metal pieces 5 and 6and a fixed contact 9 is provided on the leg part 5b of the inputterminal metal piece 5.

Then, the opening on the back surface of, the chassis (FIG. 10B) isdirected upward and the stepped part 24 of the carrier 22 (FIG. 18) isinserted in the communicating window 72 of the chassis I, then thesupporting metal piece 10 (FIG. 17) of the contact plate 12 is insertedin the concave part 1d (FIG. 10B) of the chassis and the metal piece v78is inserted in the groove 1e of the chassis to fit the contact plate.Then the coil frame 18 of the electromagnet (FIGS. 15 and 16) isinserted between the wall parts If and 1g of the chassis to fit theelectromagnet, and the coil 17 is soldered in the end part 17a to themetal pieces 78 and 66. Then the back lid 64 is secured to the bottomsurface of the chassis.

Thus the assembly of the electric parts through the opening on the backsurface of the chassis is completed. Then the opening on the frontsurface of the chassis (FIG. 10A) is directed upward. First, the hole 71is aligned with the hole 33 of the ground plate of the completedoperating part (FIGS. 12 and 14) and the operating part is fixed to thechassis with the rivet 36 (FIG. 21). Then the operatively connectingplate 25 is fitted. The indicating plate 63 indicating the trip isfitted to the U-shaped shaft 37, then the upper lid 59 is secured to theupper surface of the chassis l, the long legs 37a and 37b of theU-shaped shaft 37 are inserted respectively in the holes 57a and 57b(FIG. 20) of the handle 57, a lock washer 57b is fitted to the upperpart of the long leg 37a, a lid 79 is fixed above the long leg 37a (FIG.22) and a case is applied (FIGS. 3 and 4). Now the operation of thedevice according to the present invention shall be described in thefollowing. i. FIG. 23A shows the contact in the OFF-state in which thecontact plate 12 is separated from the fixed contact 9 (see FIG. 24A).In this case, the handle 57 is in the position of W in FIG. 2 and theindicating plate 63 is in the position of W in FIG. 6. In this case, theprojection 52 of the responding piece 49 is engaged with the end part42b of the hanging frame 42 and the shaft 41 of the turning arm 40 ispositioned at the left end ofthe arcuate groove 39 of the ground plates33 and 33' and is engaged with the inclined part 44b of the hangingframe 42. ii. When the handle 57 is rotated counterclockwise so as to bein the state shown in FIG. 23B (the handle position is in the state of Uin FIG. 2), the handle will rotate with the shaft 37a as a center, theoperating plate 38 will also rotate together with thehandle, and theupper end part 40a of the turning arm 40 will rotate clockwise with theshaft 41 as a center. Therefore, the carrier 22 will move rightwardagainst the resiliency of the spring 14 and, at the same time, thecontact will move toward ON against the resiliency of the spring. Atthis time, in case the roller (of the roller'bearing) slides while underthe reaction on the projection provided on the turning arm and passesthe apex of the projection, the displacement of the operating platewill. become maximum. When the U-shaped arm 37 further rotates and theroller lowers down the slope of the projection, the carrier 22 willsomewhat return to the OFF side. In this state, the spring 56 to returnthe handle will give a force to move the turning arm to the OFF sidebut, by overcoming it, a stable state will be made and the ON state willbe obtained, because a dead point is formed at the projection 4b of theturning arm. iii. If an excess current flows in this state (see FIG. 9),the attracting iron core 19 of the electromagnet will attract thearmature 25 and the contact will be OFF so as to be in the trip state.Its details are as follows.

Now, by the resiliency of the spring 14, the carrier 22 will be pushedtoward OFF side and this force will give a clockwise torque component tothe slope 44b of the hanging frame 42 through the turning arm and to thehanging frame 42 through the shaft 41 of the turning arm and will give atorque. When the responding piece 49 and the frame are disengaged fromeach other, the hanging frame 42 will escape clockwise and will bedisengaged from the turning arm 40 and the shaft 41 of the turning armwill move counterclockwise with the contact point of the roller andturning arm 40 as a rotation center along the groove 39. Therefore, thecarrier 22 will move to the OFF side due to the resiliency of the spring14 and the contact will be in the OFF state. At this time, acounterclockwise force (toward OFF) will be given to the operating piece38 by the handle spring 56 through the U-shaped shaft and the operatingpiece 38 will rotate. However, so that the handle may

1. An operating mechanism for driving switching mechanism in circuitbreaker having trip-indicating means comprising two ground platesconnected as spaced with each other and respectively having an arcuategroove opposing one another, an operating plate provided with verticalplates parallel with each other and with two fulcrum means set betweensaid vertical plates, said operating plate being rotatably pivotedbetween said two ground plates by means of a shaft penetrating throughthe vertical plates at one end thereof, a turning arm having at one enda shaft fitted movably in said opposing arcuate grooves of the groundplates and at the side part a cam lobe, said turning arm being looselyfitted in the middle part between said two fulcra of the operating plateand contacted in the other with a carrier communicating the operatingmechanism with the switching mechanism for driving contacts in thelatter so that the side part of the arm will be pressed against one ofthe fulcra of the operating plate by a returning force of said carrier,a hanging frame rotatably pivoted between said two ground plates so asto engage and restrain said shaft of the turning arm at one end withinsaid arcuate grooves in response to situations of the circuit and aresponding piece rotatably pivoted between said two ground plates so asto release the engagement of the shaft of turning arm with the hangingframe upon rotation due to a force transmitted to the responding piecefrom an electromagnetic device in the switching mechanism actuated whenthe circuit is in abnormal state, the arrangement being in such that,when the contacts are in ON state, the shaft of the turning arm will beengaged with the hanging frame, the cam lobe of the turning arm willengage the fulcrum of the operating plate and thereby the other end ofthe turning arm will be pushed toward the ON state of the contactsagainst the returning force of the carrier, when the contact is in thetrip state, the turning arm will be disengaged from the hanging frameand will be stably held in the trip position by the twisting forcebetween the two fulcra of the operating plate and, when the contacts arein OFF state, the shaft of the turning arm will be engaged with thehanging frame, the side of the turning arm will contact the fulcrum ofthe operating plate and the carrier will remain in the OFF position ofthe contact.
 2. The operating mechanism according to claim 1 whereinsaid shaft of the operating plate extends at one end out of the groundplate so as to be adapted to pivotally support an operating handle ofthe circuit breaker.
 3. The operating mechanism according to claim 1wherein said shaft of the operating plate is formed in a U-shape, oneleg of said U-shape being the pivot for the operating plate, the otherleg of said U-shape sHaft is penetrating through the ground plates andthe vertical plates of the operating plate so as to act as one of thetwo fulcra, and both legs extend out of the ground plate so as tosupport an operating handle of the circuit breaker in such that the oneacting as the pivot shaft for the operating plate will be a pivot shaftfor the handle and the other acting as the fulcrum will be a rotationtransmitting means between the operating plate and the handle.
 4. Theoperating mechanism according to claim 3 wherein said the other leg ofthe U-shape shaft acting as a fulcrum of the operating plate is providedwith a roller mounted therearound at the fulcrum position.
 5. Theoperating mechanism according to claim 1 wherein said force from theelectromagnetic device is transmitted to the responding piece with alarger leverage than that of the hanging frame with which the frameengages the shaft of the turning arm for restraining the arm at the oneend position in the arcuate grooves of the ground plates, and saidengagement of the hanging frame with the turning arm shaft isestablished at an inclined surface provided in the frame, said inclinedsurface forming an obtuse angle with respect to moving direction of theturning arm shaft in the grooves, so that said transmitted force to theresponding piece is further transmitted to the hanging frame as enlargedby said larger leverage and the restraining of the turning arm shaft isreadily released due to the inclined surface of the hanging frame.